Alkaline batteries are of considerable importance as a source of energy. Their long shelf life, high efficiency, long cycle life, and reasonable charge and discharge rates make them highly desirable for many applications. Little or no maintenance is required which for many applications is highly desirable. For example, alkaline batteries are often used as a source of power in remote outdoor locations. Among alkaline batteries the nickel-cadmium battery is particularly noteworthy because of its exceptionally good performance.
In order to increase the energy density of such cells, it is desirable to increase as much as possible the percent utilization of the cadmium electrode. Such increase in utilization would increase the capacity of the cadmium electrode with no increase in weight or permit equal capacity with less cadmium. Because most nickel-cadmium cells are positive electrode limited (the cadmium negative electrode has excess capacity), actual increase in the capacity of the cell requires increase in the capacity of the nickel electrode.
Also, it is desirable to improve the cycle performance of the cadmium electrode. This would ensure higher capacity over long periods of battery use and longer battery lifetimes. Better cycle performance of the cadmium electrode would permit increased capacity of the nickel electrode since less excess capacity of the cadmium electrode would be needed to ensure that the battery is positive electrode limited throughout the life of the battery.